Artillery gun barrel



Au 12, 1952 P. H. SELIN 2,606,480

ARTILLERY GUN BARREL Filed Nov. :5, 1949 2 Sl-iEETSSHEET 1 PER HJALMAR SELIN Gtforneg P. H. SELlN Aug. 12, 1952 PER HJALMAR s Luv Patented Aug. 12, 1952 ARTILLERY GUN BARREL Per Hjalmar Sclin, Bofors, Sweden, assignor to Aktiebolaget Bofors, Bofors, Sweden, a. jointstock company of Sweden Applicatien'November 3, 1949, Serial No. 125,366 In Sweden May 30,1947

11 Claims. 1

The present invention relates to military and naval guns or the like and is particularly directed to an improved artillery gun barrel in which a replaceable inner tube forms the gun bore and an outer casing affords radial support thereto and also provides therewith passages through which cooling fluid may be circulated to prevent overheating of the barrel during rapid fire.

It is accordingly a principal object of the invention to provide a barrel for an artillery gun or the like comprising a replaceable inner tube in which the gun bore is formed whereby after the bore has become scored or had its surface or dimensions altered through use or otherwise, it may be removed for repair and return or replaced by another tube with a minimum of effort.

A further object is to provide in a gun barrel of the aforesaid type interlocking means operable from the breech end of the barrel for positively securing a removable inner tube to the outer casing of the gun barrel.

A still further object is the provision of a composite gun barrel comprising an outer casing and removable inner tube with means whereby a coolant may be circulated in the interior of the barrel.

Other objects, purposes and advantages of the invention will hereafter appear or will be understood from the following description of a preferred embodiment of it illustrated in the accompanying drawings in which:

Fig. 1 is a rear elevation of a gun barrel constructed in accordance with the invention but with the gun supporting trunnions and other auxiliary apparatus omitted;

Fig. 2 is a composite fragmentary longitudinal section on angularly disposed radial planes corresponding to the lines 2-2 in Fig. 1;

Fig. 3 is a transverse section on the line 3-3 in Fig. 2 looking in the direction of the arrows, and

Fig. 4 is a fragmentary transverse section on the line 4-4 in Fig. 2 but looking in the opposite direction as indicated by the arrows.

Referring now more particularly to the drawings, the gun barrel therein illustrated comprises generally an inner tube l and, coaxial therewith when the barrel is assembled, an outer casing 2 and a locking sleeve 3 secured to the outer casing at the breech end and operative to maintain the inner tube in assembled relation therewith.

The inner tube l which provides an axial cylindrical passage 5 forming the gun bore is provided on its outer surface with a plurality of circumferentially spaced longitudinal grooves l extending from adjacent the breech to a short distance from the muzzle end of the tube and defining between adjacent grooves longitudinally extending ridges 8 the outersurfaces of which are coaxial with the bore and desirably slightly narrower circumferentially than grooves 7.

Near its forward extremity beyond the ends of grooves I the inner tube carriesga radially outwardly projecting flange 9 the outer diameter of which substantially corresponds to the inner diameter of the outer hollow cylindrical casing while between the rear ends of grooves l and the breech end of the tube integral radially projecting teeth l0 likewise corresponding at their outer or free extremities substantially to the bore of the casing are positioned respectively in axial alignment with ridges 8. w

The outer casing 2 is formed in its interior with radially inwardly projecting ridges I2 which correspond in number and circumferential spacing to ridges 8 on the inner tube and are substantially complementary thereto in contour although of somewhat greater length; adjacent ridges or ribs I2 define grooves 13 complementary to grooves 1 in the inner tube but likewise of greater axial length. The ridges 12 in the casing thus extend forwardly in the assembled gun barrel beyond the ends of grooves I in the inner tube but terminate short of flange 9 whereby adjacent grooves in the casing are in communication, while at their rear or breech ends ridges I 2 form abutments for engagement by teeth It on the inner tube when the latter are aligned therewith and so prevent the inner tube from moving forward in the casing.

The locking sleeve' 3 at its forward end includes claws l5 generally complementary to teeth I0 on the inner tube and at its breech end is provided with a radially outwardly extending flange l6 overlying the breech end 'of the outer casing and having an arcuate slot l8 adapted for the reception of a fillister head screw is or other suitable retainingmeans threaded into the endofthe outercasing.

Rearwardly of the claws l5 the. locking sleeve provides an annular recess for. the'reception of packing material 20 while a ring 2i of similar material surrounds the inner tube adjacent its forward end within the casing andis held'in place byasuitable gland 22.

In the rear part of the outer casing or jacket radial holes 24 are formed connecting with the grooves 13 in' the casing,' and in the front part of the casing are other radial holes 25 also connecting with the said grooves. The holes 24, which comprise the entrance for the coolin liquid, are suitably connected to a cooling-liquid magazine or reservoir (not shown) whereby the cooling liquid can pass from the holes 24 through the longitudinal canals formed by the grooves in the casing and the inner tube or liner, and can be drained out through the holes 25 and returned to the magazine via a reduction valve (not shown) intended for reducing the pressure shocks of the cooling liquid that arise during firing.

When assembling the inner tube with the outer casing these two parts are positioned in axial alignment and the breech end of the inner tube entered into the muzzle end of the outer casing while ridges 8 and teeth ID on the former are radially aligned with grooves l3 in the latter; the tube then can be readily slid into the casing until the teeth 10 are brought to a position in which they can clear the breech ends of ridges l2 when the tube is thereafter rotated relatively to the casing about their common axis. During this operation if the locking sleeve is already properly in place the teeth In on the tube telescope with the claws [5 on the sleeve, or if the latter is inserted after the inner tube has been positioned axially in the casing the claws on the sleeve and inner tube telescope as the sleeve is pushed home. The sleeve andtube are then rotated as a unit to bring the ridges on the tube into circumferential alignment with those in the casing and correspondingly bring the grooves in the sleeve into alignment with those in the casing, with the teeth l0 overlying the ends of ridges l2. Screw I9 is next inserted in slot l8 and/or set up therein and the locking sleeve thereby secured in fixed relation to the casing. After assembly of the inner tube in the casing the packing at the muzzle end may be adjusted to insure a fluid tight connection and the barrel is then ready for use, the necessary connections for the coolant passages being made in the normal manner if desired. I

When it becomes necessary to remove the inner tube for repair or replacement the screw l9 may be loosened and the locking sleeve rotated to the extent permitted by the arcuate slot 18, thus returning ridges B on the inner tube as well as the teeth I0 adjacent the rear end thereof to longitudinal alignment with grooves l3 in the casing, the gland 22 and forward packing ring 2| loosened or removed and the tube then withdrawn axially from the casing through its muzzle end; the same tube after repair or another similar but new tube may thereafter be inserted and assembled in the casing by reversal of these operations to restore the barrel to original operative condition.

While I have herein described one embodiment of my invention with considerable. particularity it will be understood I do not desire or intend thereby to be limited or confined in any wayas changes and modifications in the form, structure and relationship of the several parts will readily occur to those skilled in the art and may be made if desired without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus described my invention, I claim and desire to protect by Letters Patent of the UnitedStates: V v

1.'In a barrelfor guns of the type described, an outer casing'h'aving a plurality ,of longitudinal grooves on the inner surface thereof and a separable inner tube having an equal number of longitudinal grooves in the outer surface thereof, the radial thickness of the casing and inner tube walls at the grooves being substantially less than at the ridges therein, and means for releasably securing said casing and said inner tube coaxially together, the ridges between said grooves being slightly narrower than said grooves and said ridges in said inner tube and on said .casing being adapted to lie in register radially when the barrel is assembled.

2. A barrel for guns as defined in claim 1 in which said securing means include a locking sleeve adapted to interlock in non-rotative relation with the rear end of the inner tube and projecting inside the casing and screw means releasably securing the sleeve to the casing.

3. A barrel for guns as defined in claim 1 in which said securing means include a locking sleeve and interlocking axially extending teeth respectively on said sleeve and said inner tube whereby relative rotation of said inner tube and said sleeve is prevented.

4. A barrel for guns as defined in claim 1 in which forward movement of said inner tube within said casing is prevented by projections formed proximate the rear of said ridges on said tube which abut against shoulders formed at the rear ends of the ridges between the grooves in said casing.

5. A barrel for guns as defined in claim 1 in which forward movement of said inner tube within said casing is prevented by circumierentially spaced projections formed proximate and in longitudinal alignment with the rear ends of said ridges on said tube and abutting against the rear ends of the ridges between the grooves in said casing, and in which said securing means are releasably held to the casing and comprise claws telescoping with said projections to inhibit relative rotation of the inner tube and casing.

6. A barrel for guns of the type described, comprising an outer casing having a plurality of circumferentially spaced longitudinally extending grooves in its inner surface, an inner tube having a plurality of circumferentially spaced longitudinally extending grooves in its outer surface complemental to the grooves in the casing, both sets of the ridges between the respective grooves being of less width than the latter and lying in registry with each other, circumferentially spaced radially directed teeth proximate the breech end of the tube respectively abutting the adjacent ends of the ridges on the casing to thereby inhibit forward movement of the tube therein, a locking sleeve extending in the breech end of the casing around the corresponding end of the tube and having a series of claws on its inner end telescoping with said teeth to inhibit relative rotation between the sleeve and tube, and means releasably securing the sleeve to the casing in non-rotatable relation therewith.

7. A barrel for guns as defined in claim 6, including passages extending through the casing respectively to the grooves therein for direction of fluid to said grooves, and packing respectively disposed between the casing and the inner tube proximate the muzzle and the breech of the barrel beyond the ends of said grooves to inhibit leakagle of fluid therefrom longitudinally of the barre 8, A gun barrel as defined in claim 6, in which the locking sleeve is provided with a radial flange 5 adapted to extend over the breech end of the casing and having an arcuate slot and a screw extending therethrough into the casing adapted when set up to hold the sleeve in fixed relation to the casing, said slot being of sufiicient length to allow rotation between the sleeve and easing when the screw is loosened of sufficient amplitude to move the ridges on the tube out of registry with those on the casing and into registry with the grooves in the latter and thereby enable the tube to be drawn forwardly out of the casing.

9. A barrel for guns of the type described, comprising an outer hollow cylindrical casing having a series of circumferentially spaced grooves in its interior terminating short of its muzzle end, an inner tube having a corresponding series of grooves in its exterior likewise terminating short of its muzzle end, the ridges between the respective sets of grooves being of less width than the latter and adapted to register with each other i when the tube is operatively assembled in the casing, a series of circumferentialy spaced teeth extending radially from the tube proximate its breech end and respectively adapted to align with and abut against the rear ends of the ridges in the casing under like condition to thereby inhibit forward movement of the tube in the casing, a looking sleeve extending forwardly in the breech end of the casing and surrounding the proximate end of the tube, said sleeve having claws at its inner end telescoping with the teeth on the tube to thereby inhibit relative rotation between the sleeve and tube, and means releasably securing the sleeve in fixed relation to the casing whereby on release of said means the sleeve and tube may be unitarily rotated from said position to bring the ridges 0n the tube into alignment with the grooves in the casing preparatory to withdrawing the tube forwardly through the latter.

10. A barrel for guns as defined in claim 9, in which the casing is provided with passages communicating with its grooves for directing a coolant into and out of the latter.

11. A barrel for guns as defined in claim 9, including a packing ring disposed between the tube and easing proximate the muzzle ends thereof, means for compressing said packing about the tube, and a packing disposed about the tube proximate the inner end of the sleeve, said packings respectively inhibiting leakage of coolant from the grooves in either direction longitudinally of the barrel.

PER HJALMAR SELIN.

REFERENCES CITED The following references are of record in the file of this patent: l

UNITED STATES PATENT Number Name Date 1,089,078 Rabba Mar. 3, 1914 FOREIGN PATENTS Number Country Date 632,408 Germany July 7, 1936 603,976 Great Britain June 25, 1948 

